copy pixel from pixel to pixel

Hello frnd can any one plz explain the below code line by line in simple word

rgbImage = imread('861.jpg');
bs=64;
ca = mat2cell(rgbImage,bs*ones(1,size(rgbImage,1)/bs),bs*ones(1,size(rgbImage,2)/bs),3);
plotIndex = 1;
a=zeros(size(rgbImage),class(rgbImage));
aa = mat2cell(a,bs*ones(1,size(a,1)/bs),bs*ones(1,size(a,2)/bs),3);
aa(2,3)=ca(2,3);
amtx = cell2mat(aa);
imshow(amtx)

[Dishant Arora]

Why not put a breakpoint over first line of your code and move on line by line using step , step in to the called function(you can see all thes icons next to run icon in the editor window ), analyze the workspace and progress step by step. This is what I do when I don't understand a piece of code.